1. Field
One or more embodiments of the present invention relates to a method, medium, and apparatus for controlling a sound field in an array speaker system including a plurality of speakers, and more particularly, to a method, medium, and apparatus for controlling a sound field which can transmit sound only to a listener in a predetermined area by controlling a sound field in such a way that sound outputted from an array speaker is focused on the predetermined area.
2. Description of the Related Art
An array speaker is used to control direction of sound reproduced by combining a plurality of speakers or transmit sound to a predetermined area. Based on a principle of transmitting sound, generally called directivity, a plurality of sound source signals are transmitted to a predetermined direction by overlapping the sound source signals so that the strength of the sound source signals increases towards the predetermined direction by using phase differences of the sound source signals. Accordingly, such directivity is realized by disposing a plurality of speakers based on predetermined locations, and controlling sound source signals outputted from each speaker forming an array.
Recently, as various mobile digital devices are commercialized, consumption of speakers that can reproduce sound signals is increased. Accordingly, expectations and desires of users regarding a sound reproducing function of mobile digital devices are also increased. In other words, an advanced speaker technology is required, for example, a conventional mono speaker is developed into a stereo speaker, and a stereo speaker is developed into an array speaker with multi-channels. Specifically, as portable sound devices, such as miniaturized digital devices like a digital multimedia broadcasting (DMB) devices, portable multimedia players (PMPs), and mobile phones for image communication are popularized, a focusing technology, which focuses sound to a predetermined area desired by a user by using an array speaker is required. An area formed so that only a listener can listen to sound by such focusing technology is called a personal sound zone.